(i) Field of the Invention
This invention relates generally to packages of filamentary yarn used as feedstock for spiraling machines; process for making the packages; and process for using the packages; and the reinforced hose thereby obtained.
(ii) Prior Art
Spiralers are extremely old in the art. Spiralers are machines which form continuous spirals of yarn in a process that involves end-unwinding of the yarn from a feedstock package rotated at high speed. Commercial spiraling machines include those made by Knitting Machine Corp. of America, Entwistle and Sidney. Only recently have spiraling machines been developed that are capable of operating at 1,500 RPM as opposed to 700 RPM.
Reinforced hose, such as garden hose, automotive heater hose, and industrial hose, is typically manufactured by well-known processes in which a spiral of yarn formed by a spiraler is continuously coated with molten synthetic material or thermosetting elastomers. For example, see FIG. 3A described hereinafter and U.S. Pat. No. 4,155,790 (Galloway).
Prior art feedstock packages of yarn for spiralers, it is believed, have always been in the form of cones. For example, see spools S of FIG. 1 of U.S. Pat. No. 4,155,790. Further, the yarn, particularly polyester yarn formed from circular filaments, has generally been adhesive-treated yarn. This is partly because cones of untreated yarn, i.e., "greige" yarn, are incapable of performing satisfactorily at high package rotation speeds of around 1,000 rpm. It is also partly because about two thirds of reinforced hose made today has inadequate bond strength unless the yarn is adhesive-treated. It is well known that adhesive-treating of the yarn adds very significantly to its cost of production.
One type of yarn typically used in the manufacture of hose is conventional high tenacity polyester continuous filament yarn cross-wound onto a cone. Apparently, this type of yarn, a so-called industrial yarn, has never previously been wound onto a "king spool". King spools are extremely old in the art. A king spool may be defined as a spool that has one flange and only one flange, and the surface of the flange contacting the yarn is frustoconical. Thus, a cross-section of the yarn in the plane through the axis of the spool, is generally a parallelogram. See, for example, Ottko Textilmaschinen's technical leaflet "Precision Cone Winding Machine, NGS 10, for Sewing Threads", or Dietze Schell's equivalent bulletin. King spools have been used, for example, in packages of sewing thread yarn for at least twenty-five years. However, use of such sewing thread packages has apparently never involved either spiraling or rotation of the package, or yarn having a twist of less than 5 tpi.